Kirsty Humphrey, 23, posted pictures on Facebook of her daughter in her new uniform on her first day at school. The following morning her five-year-old daughter found her mum dead at their home. Police are questioning a man on suspicion of murder
The girl has been left an orphan as her dad Aaron Smith, 20, died before she was born.
Armed police officers were called to an address in Colchester, Essex by paramedics, where they found Ms Humphrey's body.
Mark Paul Czapla, 24, was later arrested by police in Colchester in connection with the incident.
Tributes have been paid to the 'dedicated' mother, who took her young daughter to school for the first time yesterday.
Joanne Moore, 29, who lives across the street from the scene, said: "She was a lovely girl and a brilliant mum. It's heartbreaking as she had only just taken her five-year-old daughter to school for the first time yesterday.
"We knew each other as our kids sometimes played together and she was the kind of person who was always help out if she could. She didn't deserve that."
A female neighbour, who refused to be named, said the Ms Humphrey and Czapla lived together.
She added: "I saw them both yesterday afternoon laughing and joking with the little girl. They were laughing and smiling between each other."
An Essex Police spokesman said: "Police have arrested a 24-year-old man in Colchester at 10.50am today on suspicion of murder as part of their enquiries into the death of a woman at an address in Queen Elizabeth Way, in Colchester."